Exhaust gas treatment devices, e.g., catalysts and particulate filters, usually have at least one exhaust gas treatment element, namely in particular at least one particulate filter element or at least one catalyst element. The respective exhaust gas treatment element is supported radially on a housing of the exhaust gas treatment device over a bearing material. The bearing material may be a bearing mat, which is pressed radially into the housing on insertion of the exhaust gas treatment element. The bearing material protects the exhaust gas treatment element from coming directly in contact with the housing and also has a vibration-damping effect, for example. This is necessary in particular when the respective exhaust gas treatment element is made of a very stiff or brittle material. For example, such exhaust gas treatment elements are made of a ceramic material, e.g., cordierite, in which case the respective exhaust gas treatment element may also be manufactured as a monolith. In addition, the bearing material usually has an axial fixation of the exhaust gas treatment element inside the housing.
The flow-through resistance of the exhaust gas treatment element introduces into the exhaust gas treatment element an axial force that drives the respective exhaust gas treatment element in the direction of flow of the exhaust gas. With a greater burden on the exhaust gas treatment element, e.g., with soot or any other impurities, the flow-through resistance of the exhaust gas treatment element increases. Furthermore, vibrations occurring during driving operation, e.g., in off-road operation of a vehicle, may likewise produce a longitudinal acceleration of the exhaust gas treatment element relative to its housing. Axial contact between the exhaust gas treatment element and the housing is to be avoided to reduce the risk of damage to the exhaust gas treatment element. It is fundamentally possible to support the exhaust gas treatment element axially on the housing with the help of a supporting device. Such a supporting device may have, for example, a receptacle for holding a wire mesh ring, which is supported axially on the respective exhaust gas treatment element. Said receptacle may then in turn be attached directly to the housing.
However, it has been found that extremely high compressive forces act on the respective exhaust gas treatment element in exhaust gas treatment systems designed for large-volume internal combustion engines, but this leads to a high load on the supporting device accordingly. Furthermore, with exhaust gas treatment elements of a large size, the bearing material must also be of large dimensions accordingly, so a radial gap which must be bridged with the help of the respective supporting device also becomes larger accordingly. In the case of a receptacle attached directly to the housing, this leads to greater loads due to the greater lever forces. Accordingly, with unfortunate constellations of load state and driving operation, there may be damage to the supporting device, which leads to the risk of damage to the exhaust gas treatment element.